All through human evolution we have been harnessing increasingly effective forms of energy. From human power to horse power, to wood, coal, natural gas and uranium what we’ve been doing is searching for the highest energy density to make energy production more efficient.

Just when major miners thought it was better to ditch their diamond divisions, giant Rio Tinto (LON, ASX, NYSE: RIO) says it is looking at the business with renewed enthusiasm, as a deposit the company discovered in India in 2004 has started to bear its shiny fruits.

Accusations of Chinese miners being dubiously brought into the Canadian province of British Columbia to work in coal mines has prompted the federal government not only to investigate the issue, but to review its entire temporary foreign worker program.

Centerra Gold (TSX:CG) was trading low on Thursday morning, after the Canadian gold miner reported Wednesday night a $46.8 million quarterly loss due to higher costs and severely lower production at its Kumtor mine in Kyrgyzstan.